Pyrotechnıc Shock Analysıs of Inertıal Navıgatıon Systems Integrated on Land Platforms

Abstract

Inertial Navigation Systems (INS) are widely used in many industries such as defence, aerospace, automotive and robotics. When considering war situations, especially designed these systems for military purposes are of great strategic importance. These systems operating on military platforms which have heavy weapons (battle tanks, aircraft, navy ships, submarines, howitzers, etc.) are exposed to severe operating conditions. In the military platforms, INS’s are expected to perform under severe conditions like temperature, vibration, shock. Shock environments, in particular, can cause damage to those devices consisting of mechanical and electromechanics systems. Therefore, necessary activities have to be carried out in order for these systems to function properly under shock during the design and development stages. The aim of this thesis is to predict the negative effects that may occur on the system due to pyrotechnic shock by performing the shock analysis of an INS operating under pyrotechnic shock on land platforms. Within the scope of the thesis, the behaviours of the sensitive unit of the INS which is the most important sub-component to be used in land platform under shock are investigated.

In this thesis, the finite element model of the system to be used in shock analysis is developed in finite element simulation software ANSYS. At this stage, the experimental modal analysis of the system is performed and the modal analysis results in the simulation environment are examined. Thus, it is aimed to verify the finite element model of the system on a modal basis. By using verified finite element model, shock analyses are performed for different classical shock pulses. Also, experimental shock tests are performed with same shock signals in order to validate the numerical results obtained from shock analyses in laboratory condition. For analysing the system which exposed to the real shock environment, shock data is obtained from field tests. Due to the complexity of these collected shock data, they are examined in terms of severity levels using Shock Response Spectrum (SRS) method and damage potential of them are compared in order to determine the input pyrotechnic shock data to be used in analysis. Finally, pyrotechnic shock analyses of the INS are performed with determined shock data. In conclusion, all information about effect of the pyrotechnic shock environments on the system has been obtained from analysis results in order to be able to evaluate whether the system can withstand these severe environment conditions.

Keywords: Finite Element Model, Finite Element Analysis, Shock Analysis, Shock Response Spectrum